1. Field of the Invention
The present invention relates generally to storage systems and data protection.
2. Description of Related Art
Small business organizations often have difficulty maintaining skilled employees for the management of storage systems, and also prefer to avoid the large upfront expenditure on their own mass storage system. Further, such organizations generally want storage capacity that is simplified and easily managed. One solution for these businesses is the outsourcing of the storage management and capacity by using a storage system that is installed at a third party data center, and maintained and operated by a storage service provider (SSP). Under this situation, data protection, which often requires complex operations such as paring of volumes, creating snapshots, monitoring network status, and planning total storage capacity, should be easily maintainable for both the small business storage customer and the SSP itself. Methods for data protection are disclosed in U.S. Pat. Appl. Pub. 2003/0126101 to Kenji Yamagami, filed Dec. 27, 2001, the disclosure of which is incorporated herein in its entirety.
One technique for facilitating ease of maintenance and operation of storage technology is through the application of virtualization to some parts of the system. A virtualization apparatus provides a virtual volume whose data is stored in a real volume in a first storage system. When the data on the virtual volume is copied to a mirror secondary volume in a second storage system, a management terminal may be used to issues commands to establish a path between the virtual volume and the secondary volume, and the management terminal may be used to control copy operations such as suspending or resuming copy. However, such a management terminal needs to be able to recognize the physical resources of the target secondary storage system in order to set up the remote copy function, which is not easily managed. Further, if the data is copied to the secondary volume from the primary volume, rather than from the virtual volume, then if the primary volume fails, recovery or continuing data writes to the secondary volume may be difficult to accomplish. Virtualization technology is disclosed in US Pat. Appl. Pub. No. 2004/0257857 to Yasutomo Yamamoto et al., filed Oct. 9, 2003, the disclosure of which is incorporated herein in its entirety.